Prior art
Molded plastic products such as plastic packaging films and containers, agricultural plastic films, binding tapes and so on are sometimes disposed of in ways other than legitimate routes of disposal. Because these products retain their shapes for years, they present serious environmental problems when discarded as they are. Therefore, it is highly desirable that any shaped products that are liable to be discarded in the open field, farmlands, rivers, etc. be those which will be rapidly decomposed by microorganisms in the soil or water.
Against this background, much development work has been undertaken to develop biodegradable compositions for the fabrication of such biodegradable shaped products. Referring to research and development along this line, the following patent applications have been filed in the technical field of bio-degradable or disintegratable compositions each comprising a saponified ethylene-vinyl acetate copolymer (i.e. ethylenevinyl alcohol copolymer) and a starch-based macromolecular substance.